Wheat Developmental Traits as Affected by the Interaction between and Temperature under Contrasting Photoperiods with Insensitive Background.

Earliness () genes are important to fine tune adaptation, and studying their probable pleiotropic effect on wheat yield traits is worthwhile. In addition, it has been shown that some genes interact with temperature and therefore determining the likely × temperature interaction is needed for each newly identified gene. We studied two NILs differing in the newly identified (carrying insensitive -D1 in the background) under three temperature regimes (9, 15 and 18 °C) and two photoperiods (12 and 24 h). affected time to anthesis as expected and the - allele extended both the period before and after terminal spikelet. The interaction effect of × temperature was significant but not cross-over: the magnitude and level of significance of the difference between NILs with the or allele was affected by the growing temperature (i.e., difference was least at 18 °C and largest at 9 °C), and the differences caused due to temperature sensitivity were influenced by photoperiod. The rate of leaf initiation was faster in NIL with - than with the allele which compensated for the shorter duration of leaf initiation resulting in similar final leaf number between two NILs. - consistently increased spike fertility through improving floret primordia survival as a consequence of extending the late reproductive phase.